This runs at startup of anything, so we should be extra sure to not
break anything, and lots of things can go wrong downloading files from
the internet
We should be creating the directory because the static tree from the
repo isn't actually copied into the container, so we can't rely on it
existing.
And if we can't write it, we should catch that error instead of crashing
the whole thing, oops!
We can't bake the font into the Docker image as such, because we mount
the volumes which blows away anything we have in the app tree
beforehand.
We could stash it somewhere in the image and then copy it from there on
app startup or something, but at that point we might as well just
download it as part of the app startup.
